| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a boxed-heart square bar which can retain its strength and generates no crack and bend and the like occurring due to dryness and to provide a dryness pretreatment method and a usage method of the boxed-heart square bar.SOLUTION: On four-material surfaces of a boxed-heart square bar 1 which has positive angles and sides of 120 mm and made of cypress, two slits 6 and 7 are positioned in a longitudinal direction in parallel with each other, the slits are positioned at 42 mm from a corner part of an adjacent material surface, and have a groove depth of 8 mm or more and 10 mm or less, and a groove width of 2 mm or more and 3 mm or less.</p> |
